In related art, a USB receptacle (also referred to as a USB port fixing device) generally comprises a casing and a receptacle chip provided in the casing. The inner wall of the casing spaces away from the outer surface of the receptacle chip. The casing is made of metal sheets with good elasticity. A USB port generally comprises a casing and a port chip provided in the casing. The side of the port chip on which conductive contacts are provided keeps a distance away from the inner wall of the casing, wherein said distance is equal to the thickness of the receptacle chip in the USB receptacle. When performing data transmission as needed, the USB port is inserted into the USB receptacle, the receptacle chip of the USB receptacle is inserted into the gap between the inner wall of the casing of the USB port and the port chip, and the USB port is inserted into the gap between the inner wall of the casing of the USB receptacle and the receptacle chip, so that the conductive contacts on the port chip come into contact with the conductive contacts on the receptacle chip. In this case, the inner wall of the casing of the USB receptacle comes into tight contact with the outer wall of the casing of the USB port, to force the casing of the USB receptacle to be elastically deformed outward (i.e. in a direction away from the receptacle chip) so as to clamp the USB port. When the data transmission is over, the USB port is detached from the USB receptacle. Then, the casing of the USB receptacle is restored due to the detach of the inner wall of the casing of the USB receptacle from the outer wall of the casing of USB port. It can be seen that the USB port is fixed to the USB receptacle by the elastic deformation of the casing of the USB receptacle. However, such USB receptacle has the following disadvantages.
(1) In order to fix the USB port steadily so as to make the USB port not easy to fall off from the USB receptacle, it is usually designed to form an interference fit between the inner wall of the casing of the USB receptacle and the outer wall of the casing of the USB port. As result of manufacture processes or the like, sometimes the engagement between the USB port and the USB receptacle is too tight, which leads to difficulty in insertion/extraction of the USB port.
(2) When the USB port is inserted/extracted for too many times, the deformation of the casing of the USB receptacle is not readily to be restored sufficiently, which leads to poor contact between the conductive contacts on the port chip and the conductive contacts on the receptacle chip. As a result, the signals may be unstable, and the USB port may easily fall off from the USB receptacle.
At present, for the purpose of lightweight and thinness, the USB port without a casing has been developed. In the USB receptacle that cooperates with such USB port, the side of the receptacle chip on which conductive contacts are provided keeps a distance away from the inner wall of the casing of the USB receptacle. The port chip of said USB port is directly inserted into the gap between the inner wall of the casing and the receptacle chip of the USB receptacle, so that the conductive contacts on the port chip come into contact with the conductive contacts on the receptacle chip. However, such USB receptacle also has the above disadvantages.